1. Field of the Invention
The invention is related to a fuel injection valve for internal combustion engines.
2. Description of the Prior Art
In a fuel injection valve of the type with which is invention is concerned, which is known from DE 39 00 763, a valve member is guided so that it can move axially in a guide bore of a valve body. With its end oriented toward the combustion chamber, the valve member controls a through flow cross section to at least one injection opening into the combustion chamber of the engine to be supplied. With its end remote from the combustion chamber, the valve member protrudes at least indirectly into a fuel-filled spring chamber in which a valve spring is clamped that acts on the valve member in the closing direction of the through flow cross section. This valve spring is supported with its end remote from the valve member against a deflecting piston which, during the supply of high fuel pressure to the fuel injection valve, can be moved a certain distance into the spring chamber and by means of this insertion, increases the initial stress force of the valve spring. The preinjection in the fuel injection valve is controlled by means of this increase in the initial stress force of the valve spring during the injection phase. The spring chamber containing the valve spring has a connecting conduit to a low pressure fuel chamber encompassing the valve body of the fuel injection valve. This low pressure fuel chamber is embodied as an intake chamber for a high pressure fuel pump which, together with the fuel injection valve, constitutes a component and is connected to the fuel injection valve by means of a clamping nut. This component is then inserted into a corresponding receiving opening of the housing of the engine to be supplied, wherein the control of the high pressure delivery to the high pressure fuel pump and consequently the high pressure fuel injection at the fuel injection valve takes place by means of an electric control valve, preferably a solenoid valve, which is connected laterally to the housing of the high pressure fuel pump.
In this connection, however, the fuel injection valve has the disadvantage that the closing force of the valve spring is not enough to also produce very high injection opening pressures in the fuel injection valve. Furthermore, with the known fuel injection valve, when the valve member is opened rapidly, an oscillation of the valve spring and consequently also of the components connected to it--particularly of the valve member--can occur, which has a disadvantageous effect on the actually prevailing injection opening pressure and as a result, on the metering precision of the injection quantity in the fuel injection valve.